Electrohydraulic steering gear



Oct. 10, 1939. F. s. HoDGMAN 2,175,800

ELECTROHYDRAULIC STEERING GEAR Original Filed Jan. 14, 1937 2Sheets-Sheet l 69 INVENTOR Y 25 figgasmck/bosnnlv F. s. HQD'GMANELECTROHYDRAULIC STEERING GEAR original Filed Jan. 14'. 1957 2sheets-sheet 2 INVENTOR /vEnEnlc/f H ORNEY,

Patented ct.V 10, 1939 ELECTROHYDRA'ULIC STEERING GEAR Frederick S.Hodgman, Glen Rock, N. J., assignor to Sperry Gyrscope Company, Inc.,Brooklyn, N. Y., a corporation of New York Application January 14, 1937,Serial No. 120,482 Renewed March 2, 1939 Claims.

This invention relates to hydraulic or combined electro-hydraulicsteering gear for ships and other drigible vehicles.

The standard steering system for many ships 5 consists of two hydraulictelemotor units, one at the forward end and one at the after end,connected by long piping, the forward end being actuated directly fromthe main pilot wheel which operates the after end by transmission offuid l0 pressure through the connecting pipes. 'AIhis system has theadvantages of simplicity and direct operation between the two units, butit also has the disadvantages of requiring considerable effort tooperate, requiring extensive piping and being subject to loss ofsynchronism by leakage of uid and ingress of air.

According to my invention, I propose to supplement such a standardhydraulic telemotor steering by an electro-hydraulic system whichparallels the hydraulic system from the pilot house to the after end,but which preferably makes use of the after telemotor unit forIoperating the rudder either directly or through the usual steeringengine. According to my system, I provide an auxiliary oil pump at theafter end to supply the iiuid pressure necessary for moving the rudderwhen operating through the electric steering wheel and also provide apair of throw-over valves to cut in and out the hand telemotor and.

power system alternatively so that either may be used, but when one isin use the other system is locked out.

My system is also readily adapted for automatic steering for ships,since the form of controller in use at the pilot house is readilyadapted for automatic steering uses.

My invention contains certain improvements over the electro-hydraulicsystem shown in my prior application Serial No. 83,216, led June 3,

Referring to the drawings,

Fig. 1 is a diagrammatic view showing my invention applied to the usuallships telemotor system.

Fig. 2 is a longitudinal section of one of the throw-ever valves in aposition different from that shown in Fig. 1.

Fig. 3 is a transverse section through the master control Valve operatedfrom the electric steering Wheel.

Fig. 4 is a simplified wiring diagram of the electric steering gear.

As explained above, the usual ships telemotor steering system comprisesa pilot wheel I which v operates usually one or more vertical racks 2through pinion 3 and bevel gears 4. In this case the rack 2 is shown asconnected to the piston rod 5 of a hydraulic cylinder 6, one end ofwhich is connected to a pipe 'l and the other end to a pipe 8 leadingaft to the after telemotor unit. 5 A by-pass valve 9 is shown for thepurpose of synchronizing or throwing out the forward unit. Usually thepipes 'I and 8 lead directly to the after cylinder or cylinders I0', thepiston 50 of which is centralized by spring and is conl0 nected to therudder R or to the valves of the steering engine through cables or othermechanical linkage 8l. According to my invention, I lead the pressure'duid first through a. pair of throw-over valves II and I2 located inpipes 1 l5 and 8, respectively. With the piston valves II and I2 in thepositions shown, the pressure iluid from the cylinder 6 passes throughthe valves and on to the actuating cylinder IIJ through pipes 1' and 8.Normally, the piston valves i I', l2' are 20 held in the position shownin Fig. l by compression springs I3 and I3', which bear at one endagainst the fixed interior collar or ring I4 in each cylinder and at theother end against an outer piston I5 secured to the stem I6 of saidvalve. 25 In case, however, fluid under pressure is admitted throughpipe I1 into the left hand end of cylinders II and I2, each piston valvewill be forced to the right to compress said springs, as shown in Fig.2, in which position the ports communi- 30 eating with pipes 1. and 8are'shut oi, and at the same time the pipes 1' and 8 are respectivelyconnected to pipes I8 and I8' connected with a rotary master valve I9controlled from the electricsteering wheel. 35

Said master valve is shown as having, in addition to ports communicatingwith pipes I8 and I8', two ports communicating respectively with pipes2li and 2l leading to the pressure and re' turn side. respectively, of ahydraulic pump-22, 40 shown as driven from an electric motor 23. Saidpump draws its fluid from a sump or reservoir 24- through a pipe 25. Aby-pass pressure regulating relief valve 25 regulates the pressuresupplied by the pump to the system, returning or 45 by-passing to thesump excess iiuid not required for the operation of the system.

The valve is shown as of the rotary, balanced type turnable into any oneof three positions: (1) in which the pump pressure from pipe 20 50 andthe return to pipe ZI are both cut olf, as shown in Fig. 3; (2) in whichthe valve is rotated clockwise through about 20, thus connecting thepressure pipe 20 to pipe I8 so that pressure is supplied through valveII and pipe 1' to the 55 upper end of cylinder l0 to the rudder to turnthe rudder in a counter-clockwise direction from the position shown inthe drawings. At the same time the return side is connected to the pipeI8 and thence to pipe 8' through the transverse channel 21 through thecenter of the rotatable valve. (3) In the third position the Valve isrotated in a counter-clockwise direction about from the position shownin Fig. 3, to connect pressure pipe 20 to pipe I8' so that pressure issupplied to the lower end of cylinder I0 to move the rudder in the otherdirection. At the same time the return side of the line 2l is connectedto the pipe I8 through the passage 2l.

through the valve, leading to a closed chamber 29, so that the valve isbalanced in all positions.

The valve is positioned in its several positions from an electromagneticdevice, shown as in the form of a motor 3U, the shaft of which is gearedto the shaft 3i of the valve through bevel gearH ing 32. The movementsof the motor shaft are, however, limited in both directions so that thevalve will only be turned through the correct angles, and the armatureis normally centralized by a stiff spring or springs. Preferably themotor` is constructed as shown in detail in my prior application SerialNo. 83,216, for Electro-hydraw lic telemotors, filed June 3, 1936. Inthis applicau tion I have merely represented this construction byshowing an arm 34 secured to the motor shaft 35 and centralized on eachside by compression springs 36 and 36', and limited in its movement byfixed stops 3l and 3l" (Fig. Ll). The motor shaft is normallycentralized so that the valve I9 is in the position shown in Fig. 3,which is the standstill position of the rudder, but movement of the meershaft in one direction or the other causes movement of the rudder, asexplained above.

The motor 30 is preferably controlled from a controller or controllersand/or te, preferably adjacent the main pilot wheel4 E. The controller38 is shown as of the follow-up type and is actuated by a small pilot ortrick Wheel Ml which is shown as rotating the split Contact rings it andY 42 which control the motor 3d. Said contact rings together with theirslip rings Al and QE' are shown as mounted on the face of a large bevelgear 90 with which a bevel pinion it on the shaft of hand wheel 4Gmeshes. The revolving brushes or trolley arm d3 of said contacts isshown as rotated from a repeater motor dit, said motor, in turn, beingactuated by a transmitter i6 driven directly or indirectly from therudder or the telemotor IB actuating the same. As shown, the transmitteris driven from a rack bar t8 secured to the piston rod 49 of the piston5cl within the cylinder Ill, the transmitter and motor being shown as ofthe A. C. self-synchronous type and making not more than one-halfcomplete turn for a hard-over to hard-over rudder movement.

The controller is shown as operating the motor 30 through a relay 5E,the controller indirectly energizing one or the other of the coils 52and thereon to close one or the other of pairs of contacts 9| or S2 tosend current through the armature of the motor 3i! in one direction orthe other. The leads from the controller, however, are rst carriedthrough a magnetically operated switch 54, which is normally held closedas long as the A. C. supply for the self-synchronous transmitter 46 andmotor 44 does not fail. The Winding 55 thereof is in circuit with saidsupply and holds contacts 59, Ell and 6l normally closed.

There` `is also shown an axially spaced passage 2E -tric system.

In case this supply fails, however, the biased contacts 59, 60 and Elopen, thus disconnecting the follow-up controller 4I and connecting anauxiliary hard-over controller 39 by closing back contacts 59', 60 and6|. The operator may then steer through said hard-over controller 39,which is shown in the form of a push rod having a handle 69, a cross arm68, and a bridging contact which, in the position shown in the drawings,close a circuit between the contacts 58 and 58 placed between one of theA. C. supply leads and the coil 55.

The cross arm 68 is in operative position over a pair of spring biasedreversing switches l0 and 'H which are in circuit with back contacts59', 6U and 6I on the relay 54, which contacts are closed when thecontacts 5S, 6U and 6i are opened. It will readily be seen, therefore,that by rocking the handle 69 in one direction or the other, the

`motor 30 will be operated in the same manner as from the follow-upcontacts. Since there is no follow-back connection, the rudder willtherefore be run over when one of contacts lll or ll is held down aslong as the contact is depressed and until its limit is reached, suchlimit being the limiting movement of piston in cylinder i0. It is alsoobvious that the operator may assume control with the hard-overcontroller 39 at any time desired by merely pulling out the push rod,which will break the circuit to coil and thereby dis connect thefollow-up controller and render the hard-over controller operative. Thefollow-up controller is shown as having thereon a controller positionindicating pointer l2 driven from large bevel gear dll through bevelpinion 92 and shaft 93. Said pointer is readable onv a fixed scale 94.

The pump 22 is also preferably controlled from a switch. l5 on theelectric controller stand lll. Said switch preferablycontrols the motorthrough a relay7 switch ll normally biased to an open position by springi3, the switch operating toclose a circuit through solenoid l, whichholds the switch closed as long as current is owing there# through. Incase, however, the switch 'i5 is opened or in case of failure of themain D. C. supply to the relay circuits and reversing motor dit, theswitch ll will open, thus stopping the motor 25S. stoppage of the motorwill of course stop the pump 22, resulting in the valves il and l2 beingreturned to the position shown in the drawings, thus disconnecting theelectric system and restoring full hydraulic control from the mainsteering wheel l and forward telemotor By my present system, therefore,l.' secure all the advantages of electric steering and at the same timeretain the reliability of the hydraulic telemotor system by providing anautomatic throw-over from the electric to the hydraulic teleinotoi'system in. case of failure of the elec In addition, l provide two alternative electric controls, so that the hard-over controller may be usedin case cfifailure of the follow-up controller, or at any time desired.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

Thus, in case the ship on which my invention is applied were equippedwith an automatic pilot, the controller 38 would become the standardcontroller on the automatic pilot, such as shown in,

Fig. of the prior patent to Chester B. Mills, #1,695,601, dated December18, 1928, the contact rings in this instance being tu-rned diierentiallyfrom the compass repeater motor and the trick wheel 40.

Having described my invention, what I claim and desire to secure byLetters Patent is:

1. A dual hydraulic steering gear for ships, the :ombination with amanually powered hydraulic` system including a forward telemotorv unitand pilot wheel and an after telemotor unit, an auxlliary pilot wheel, apower driven pump, means for disconnecting said forward from said afterunit and for connecting said pump t0 drive said after unit, a triplevalve for governing said unit from the pump to drive the former in onedirection or the other o r to stand still, and electrical means actuatedby said auxiliary pilot wheel for positioning said valve in any of its.three positions. v

2. An auxiliary electrical control for hydraulic telemotor Vsteeringgears as claimed -in claim-1, having an electrical follow-backconnection from the after telemotor unit to said electrical means atsaid auxiliary pilot wheel. l

3. A dual hydraulic steering gear for ships, the combination'with amanually powered hydraulic system including a forward telemotor unit andpilot wheel and an after telemotor unit, an auxiliary pilot wheel, anelectrical controller operated thereby, a power driven pump forauxiliary operation of said after telemotor unit, and means forgoverning the supply of lluid pressure from said pump by said controllerto actuate the rudder to steer the ship.

4. An auxiliary electrical control for hydraulic telemotor steeringgears as claimed in claim 3,`

having automatic means for throwing out the auxiliary steering system onfailure of pump pressure.

5. In an electrical steering gear for ships, a follow-up electricalcontroller, a steering motor, a self-synchronous electrical transmissionfrom said motor to said controller, a hard-over electrical controller,and automatic means for transferring the control of said steering motorfrom said follow-up to said hard-over controller lresponsive to failureof said self-synchronous transmission.

6. In an electro-hydraulic telemotor, s controlling member, a controlledmember, a hydraulic servo motor for determining the movement of saidcontrolled member, valve means for regulating the supply of pressureoperating fluid to said servo motor, a remote control electric circuitincluding motive means for operating said valve means,4 said circuitcomprising contact means actuated from said controlling member fordetermining the operation of said motive means, an electricalrepeat-back connection between said servo motor and said contact means,and an alternative manually operated telemotor for operating said servomotor directly.

7. In an electro-hydraulic steering system, the combination with amanually powdered hydraulic system including aforward telemotor unit andpilot wheel and an' after telemotor unit normally connected together, apower driven pump for auxiliary operation of said after telemotor-unit,and automatic means in the connections between said forward and aftertelemotor units for disconnecting the latter from the former andconnecting the latter to said pump upon establishment of working pumppressure.

8. A duel hydraulic steering gear for ships, thecombination with amanually powered hydraulic system including a forward telemotor unit andpilot wheel and an after telemotor unit, an auxiliary pilot wheel, apowder driven pump, valve means for disconnecting said forward from saidafter unit and for connecting said pump to drive said after unit, asecond valve for governing said unit from the pump -to drive the formerin one direction or the other, and means actuated by said auxiliarypilot wheel for positioning said valve in any of its positions.

9.`In an electro-hydraulic steering system, the combination with amanually powered hydraulic system including a forward telemotor unit andpilot wheel and an after telemotor unit normally connected together, apower driven pump for auxiliary operation of said after telemotor unit,automatic means in the connections between said forward and aftertelemotor units for disconnecting the latter from the former andconnecting the latter to said pump upon establishment of working pumppressure, and an auxiliary pilot wheel1for controlling the applicationof pump pressure to said after telemotor.

10. Apparatus for the distant dual positional control of the rudder of adirigible craft, comprising a manually controllable hydraulic systemincluding a forward telemotor unit and pilot wheel and an aftertelemotor unit serving to' actuate the rudder, normally connected tosaid forward unit, a powder driven'hydraulic pump, an auxiliary controldevice adjacent said pilot wheel, and valve meansadlustable therefromfor disconnecting the said after unit from the for-

